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Comparison · 2 models · Updated Nov 2, 2026

Qwen3.5 9B Base vs GPT-5.1 Codex mini

GPT-5.1 Codex mini comes out ahead, 54 to 50 on our weighted score, though Qwen3.5 9B Base is 38% cheaper per token.

  1. Alibaba (Qwen)

    Qwen3.5 9B Base

    Released Feb 26, 2026

    50/100
    • ECI—
    • Price$0.30 / $0.807
    • Context262K
  2. Our pick

    OpenAI

    GPT-5.1 Codex mini

    Released Nov 13, 2025

    54/100
    • ECI—
    • Price$0.25 / $2.00
    • Context400K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

GPT-5.1 Codex mini is our pick

GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Qwen3.5 9B Base (50). It leads on inputs & features and context window. Qwen3.5 9B Base wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

  • CapabilityNot enough dataNo independent benchmark covers every model here yet
  • Lowest priceQwen3.5 9B BaseQwen3.5 9B Base $0.427 · GPT-5.1 Codex mini $0.688 per 1M tokens (3:1 blend)
  • Longest contextGPT-5.1 Codex miniGPT-5.1 Codex mini 400,000 · Qwen3.5 9B Base 262,144 tokens
  • Widest inputsQwen3.5 9B BaseQwen3.5 9B Base: Text, Images, Video · GPT-5.1 Codex mini: Text, Images
  • Self-hostingQwen3.5 9B BasePublishes downloadable weights (Apache-2.0)
How the score is built
MeasureWeightQwen3.5 9B BaseGPT-5.1 Codex mini
Price50%6555
Inputs & features30%3560
Context window20%3744
Overall100%50/10054/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Qwen3.5 9B Base vs GPT-5.1 Codex mini specifications side by side
SpecificationQwen3.5 9B BaseAlibaba (Qwen)GPT-5.1 Codex miniOpenAI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.30$0.25 (best)
Output$0.807 (best)$2.00
Cached input——
Blended (3:1)$0.427 (best)$0.688
Long-context rateSame rateSame rate
Price sourceMedian of 1 providersMedian of 16 providers
Limits
Context window262,144 tokens400,000 tokens (best)
Max output65,536 tokens128,000 tokens (best)
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoYesNo
ReasoningNoYes
Tool callingNoYes
Structured outputNoNo
Availability
WeightsOpenApache-2.0Proprietary
API model ID——
API providers116 (best)
ReleasedFeb 26, 2026Nov 13, 2025
Knowledge cutoff—Sep 30, 2024
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Qwen3.5 9B Base$4.61
  • GPT-5.1 Codex mini$6.50
04 — Questions

Which should you choose?

Which is better: Qwen3.5 9B Base or GPT-5.1 Codex mini?

GPT-5.1 Codex mini is the better all-round choice, scoring 54/100 against Qwen3.5 9B Base (50). It leads on inputs & features and context window. Qwen3.5 9B Base wins on price. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.

Which is cheaper, Qwen3.5 9B Base or GPT-5.1 Codex mini?

Qwen3.5 9B Base is cheaper at $0.30 input / $0.807 output per million tokens (median across 1 API provider). GPT-5.1 Codex mini costs $0.25 input / $2.00 output per million tokens (median across 16 API providers). At a typical mix of three input tokens to one output token, that is $0.427 per million tokens for Qwen3.5 9B Base versus $0.688 for GPT-5.1 Codex mini (1.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Qwen3.5 9B Base has not been scored yet and GPT-5.1 Codex mini has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Qwen3.5 9B Base and GPT-5.1 Codex mini yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Note that Qwen3.5 9B Base does not support tool calling, which most coding agents need.

Which has the bigger context window?

GPT-5.1 Codex mini has the largest context window at 400,000 tokens, against 262,144 for Qwen3.5 9B Base. Maximum output per response: Qwen3.5 9B Base up to 65,536, GPT-5.1 Codex mini up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Qwen3.5 9B Base accepts text, images and video; GPT-5.1 Codex mini accepts text and images. Qwen3.5 9B Base handles the widest range of inputs.

Are any of these open source?

Qwen3.5 9B Base publishes its weights (Apache-2.0) and can be self-hosted; GPT-5.1 Codex mini is proprietary.

Which is newer?

Qwen3.5 9B Base is the newest, released Feb 26, 2026. GPT-5.1 Codex mini came out Nov 13, 2025. Knowledge cutoff: GPT-5.1 Codex mini Sep 30, 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.